The task of navigating a vehicle in an unfamiliar area is difficult, time-consuming, and an inevitably frustrating experience. The frustration is most acute when one is alone in a vehicle.
Observation of such data is difficult enough. Navigational data such as street signs and building numbers reside outside of the vehicle in non-standard locations. Building numbers are often obscured by trees, shrubs, and fences, and street signs are often missing or misdirected.
Even if the navigational data can be obtained, the process of using it is even more arduous. The data must be correlated on a map or written directions situated inside the vehicle. It is a difficult and dangerous endeavor to divide one's attention between operating a vehicle and reading a map. The above-described difficulties result in a needless risk of safety, and a waste of time and effort.
Navigation inevitably begins with determining one's current position and direction of travel. This requires that a minimum of two street signs be read and correlated on the map. Once the direction is proper and the target street is located, the proper direction on the target street must be ascertained. Again, a minimum of two building numbers must be read. Once the vehicle is headed in the right direction, the operator must continuously view building numbers until the proper building is found.
The above-described repetitive process of determining one's position and direction in relation to fixed surroundings is an unnecessary diversion of time and energy from the primary task of defensive driving. This is at best an inconvenience and a source of additional expense for the commercial driver. At worst, it is a safety hazard and a cause of delay for ambulances and other emergency vehicles. The time expended may spell the difference between the life and death of a patient.
The field of the art is crowded with devices for identifying the position of a remote vehicle or object. For example, in U.S. Pat. No. 4,598,272 issued to Cox, an electronic monitoring apparatus is disclosed which enables a monitoring person to monitor the whereabouts of a monitored person. The Cox system includes a monitoring transceiver and a monitored transceiver. The monitoring transceiver prompts the monitoring transceiver to transmit a reference signal. The monitoring transceiver correlates the strength of the received reference signal with the distance between the two transceivers. The operator of the monitoring transceiver can locate the monitored transceiver by eliminating the distance between the two. The Cox system has many applications in the consumer and commercial market. For example, it can be used to prevent thefts, track deliveries, avoid loss of possessions or children, and any number of other related applications. However, the device has limited capabilities in the field of navigation. It cannot give an immediate indication of geographic position.
Numerous other prior art systems exist for the purpose of determining geographic position. These systems are typically based on a LORAN-C positioning signal. However, such systems are subject to the inherent inaccuracies of ground-based LORAN-C systems, and can provide no more than a cartographic estimate of geographic location. They do not provide specific navigational assistance to the operator of a vehicle who is attempting to locate a specific place or object.
In contrast, U.S. Pat. No. 4,857,840 issued to Lanchais discloses an information and guidance system which is capable of pinpointing its own position. However, Lanchais uses a transceiver which determines its geographic position by using an exceedingly complex methodology. Specifically, the transceiver combines a measurement of the earth's magnetic field with measurements of the distance between itself and a remote station. The combined measurements are used to determine the position. The complexity of the Lanchais system undermines its utility.
In short, none of the prior art systems fulfill the need for a simple position determining and navigational system which will efficiently direct a person to a specific place or thing.